

EM Clean: natural household cleaning with a microbial cleaner, dilutions, and limitations

One container for floors, windows, the bathroom, the patio, and even the laundry: that's the promise of microbial cleaners such as EM Clean. Lightly scented and dye-free, they appeal to people who want to declutter their cabinets and cut down on harsh products at home.
This guide gives you the right dilutions surface by surface, the techniques that make a difference, and an honest clarification: what an EM cleaner does well, what it doesn't do, and the situations where another product is still essential.
A microbial cleaner: what exactly is it?
EM Clean multi-purpose cleaner is a liquid concentrate made by fermentation. It contains water, effective microorganisms (mainly lactic acid bacteria and yeasts), and the substances produced during fermentation, including organic acids. It doesn't foam, contains no dyes, and needs little or no rinsing.
You'll often see these products called "probiotic cleaners." The term is misleading: a probiotic is a microorganism that benefits your health when swallowed. On a surface, it's simply a cleaner that contains live microorganisms and leaves some of them on whatever it touches.
In practice, what does the cleaning is first and foremost the water, the wiping motion, and the cloth. The acids from fermentation help loosen light mineral deposits, and according to the manufacturer, the microorganisms keep breaking down organic residues after cleaning, an effect that independent tests have not confirmed. The manufacturer therefore advises against rinsing: apply, wipe, and let dry.
Dilutions, surface by surface
The dosages below follow the manufacturer's instructions. Always check the label on your container, and use cold or lukewarm water, preferably unchlorinated.
Indoors
Floors: the manufacturer recommends 1% to 10%, depending on how dirty they are. For routine cleaning, 1.7 to 3.4 fl oz (50 to 100 ml) in a 2.6-gallon (10-liter) bucket (0.5% to 1%) is enough; save the stronger dilutions for heavily soiled floors. Use a well-wrung mop or microfiber cloth, without rinsing.
Countertops, tables, furniture, tile, stainless steel: 1% to 10%, depending on the dirt, in a spray bottle. Let it sit for two to three minutes, then wipe.
Windows and mirrors: 1% to 2%, no more, or you'll get streaks. Wipe with a clean microfiber cloth.
Toilets: 10% to 30% for the inside and outside of the bowl.
Rugs and sofas: vacuum first, then lightly dampen with a 1% to 10% solution and brush. Test on a hidden area first.
Washing machine: 0.3 to 1 fl oz (10 to 30 ml) of undiluted EM Clean in the fabric softener compartment.
Outdoors
Patio, outdoor furniture, greenhouse, shed: 5% to 10%, brush, then rinse with a weak dilution. For long-standing grime, the manufacturer advises starting at 20% to 30%.
Very dirty tools and objects: soak in a 10% solution for anywhere from a few hours to several days, then brush.
Emy's tipOnly mix the amount you need for each cleaning session. A dilution doesn't keep: pour what's left down the sink, the shower, or the toilet rather than leaving it in the spray bottle.
Precautions to be aware of
Never combine it with bleach
This is the most important rule. First, because bleach and disinfectants kill microorganisms: used one after the other, the two products cancel each other out. Second, and above all, because EM Clean is a fermented product rich in lactic acid, and therefore acidic, like EM solutions, whose pH is around 3 to 3.5. Mixing bleach with an acidic product releases chlorine gas, which is toxic to breathe. Every year, cases of poisoning, sometimes serious, are caused by this kind of mixture.
So keep separate buckets, spray bottles, and cloths, and never use one product right after the other on the same surface.
Be careful with limestone surfaces
Marble, travertine, limestone, and some natural stone tiles are sensitive to acids. On these surfaces, test a weak dilution on a hidden area first, or use a pH-neutral soap instead.
Sensitive skin or airways
Like any microbial cleaner, EM Clean may irritate the skin or airways in some people. Avoid breathing in the spray mist, ventilate the room while cleaning, wear gloves if you have sensitive skin, and store the container out of the reach of children.
Did you know?The bleach bottle and the EM cleaner container must never meet in the same bucket: besides canceling each other out, the two products together can release a toxic gas.
Cleaning is not disinfecting
EM Clean is a cleaner, not a disinfectant. The manufacturer says so itself. It removes dirt and reduces unpleasant odors, but it isn't intended to kill germs, and we don't present it that way.
The good news is that at home, disinfecting is rarely necessary. Regular cleaning is enough for most surfaces. Home hygiene experts recommend focusing your efforts on a few key moments, when a suitable product and stricter practices are called for:
- after handling raw meat, fish, or eggs: countertop, cutting board, and utensils;
- when someone in the household is sick, especially with a stomach bug: toilets, door handles, faucets;
- when a vulnerable person lives in the household: a baby, an older adult, or someone who is sick or immunocompromised. In that case, follow their doctor's advice;
- after contact with feces, human or animal, or with wastewater.
For surfaces in direct contact with food, we recommend hot water and dish soap, followed by rinsing. Save EM Clean for the rest of the kitchen: floors, cabinet fronts, backsplash, the outside of appliances.
Key takeawaysEM Clean is a great replacement for your usual cleaners for everyday cleaning. It doesn't replace a disinfectant in the rare situations where one is truly needed.
What the research says
Microbial cleaners are the subject of research, particularly in hospitals. But almost all of these studies concern other products, based on spores of bacteria of the genus Bacillus, not EM. So they don't allow any conclusions to be drawn about EM Clean.
Independent evaluations of EM cleaners themselves are rare. A review published in Austria in 2009 found them less effective than conventional detergents on ordinary floor dirt, but useful for reducing odors and maintaining traps and drains. Laboratory tests published in 2025 on five commercial microbial cleaners point the same way: three cleaned as well as or worse than a reference cleaner without microorganisms, and repeated applications neither improved the results nor established the microorganisms permanently on the surfaces. For odor control, see our guide Getting rid of bad odors with EM, and for drains, Septic tanks, pipes, and composting toilets.
Our take: EM Clean is a good everyday cleaner: simple, versatile, and economical once diluted, especially where odors are a problem. For heavy degreasing, black soap or dish soap is still more effective. The regulatory status of microbial cleaners is explained in our guide EM and regulations.
Storing EM Clean properly
- In a Bag-in-Box, the concentrate keeps for up to a year, even after opening, because the bag contracts without letting air in.
- Store it in a cool place, away from light and freezing temperatures, like other EM products. The general rules are in our guide Getting started with EM.
- Slight variations in smell or color from one batch to the next are normal for a fermented product. A distinctly putrid smell, however, means the product should no longer be used.
In summary
EM Clean is a fermented cleaner based on effective microorganisms, used diluted in water, from 0.5% for floors to 30% for toilets, without rinsing. It's suitable for most surfaces in and around the home, and it's especially useful where odors keep coming back. Never combine it with bleach, test it on limestone surfaces, and mix your dilutions fresh each time. It's not a disinfectant: for raw meat, someone who is sick or vulnerable, or wastewater, use the appropriate practices and products.
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